switch – Allied Telesis AT-9424T/SP stuck in bootloop

I’m facing a boot loop issue with my Allied Telesis AT-9424T/SP switch. After powering it on, the system initializes and attempts to decompress the application image, but it eventually throws an exception and restarts. I suspect the issue might be due to an incompatibility between the bootloader and the application firmware versions. Here’s what I’ve tried and observed so far:
1. Console Output During Boot:

Boot Loader (ROM) information:
Product Name: ATS63_LOADER
Product Version: v3.2.1
Build Date: Jul 1 2009
Build Time: 11:31:24

System information:
SDRAM: 32MB
CPU speed: 200MHz

Decompressing the Application Image, please wait…………………………..
…………………………………………………………………..
…………………………………………………………………..
…………………………………………………………………..

Decompressed 3255604 bytes from Flash to 11404256 bytes into RAM
Jump to 0x00000100 to start application

2.  Exception Message:

Initializing LoopGuard ….

FATAL – Exception
Bootloader: ATS63_LOADER v3.2.1 Cycle_A Jul 1 2009 11:31:24
Application: ATS63 v2.11.6J Cycle_C Jul 22 2013 11:34:29
Module: Init 15:48:29 on 20-Nov-2024

GPR0 = 00004e78 GPR1 = 00d16194 GPR2 = 00ada780 GPR3 = a54b962d

Exception Vector: 00001100/Address error at 0062dbe8

I’ve Attempted So Far:
• Tried accessing the bootloader by pressing Ctrl + B, Ctrl + C, and Esc during boot.
• Adjusted serial connection parameters to 460800 bps (default) and even 9600 bps for troubleshooting.
• Identified that the versions of the bootloader (2009) and firmware application (2013) differ, which may be causing the issue.
• Tried using the reset button (SW1) on the board but didn’t notice any change.

My Questions:
1. Is the difference between the bootloader and firmware versions likely the cause of this issue?
2. How can I force the switch into ROM Monitor mode if no keys seem to interrupt the boot process?
3. Can the SW1 button be used for resetting the device or forcing it into a recovery mode? If yes, how?
4. Is it possible to update the bootloader via XMODEM or another method without accessing the application firmware?

I appreciate any insights or guidance from those who’ve encountered similar issues. Thank you!

UPD: Some photos of motherboard. Maybe short circiut some contacts will force enter in boot mode?
enter image description here

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